Heating boiler



April 7, 1031. RAINCHON HEATING BOILER Filed May 15, 1929 IIQVEIVIT'OR i6. t

)TTYS.

of the Patented Apr; 7, i931 UNITED STATES PATENT OFFICE HEATING BOILER Application filed May 13, 1929, Serial No. 862,805, and In the Netherlands Augnst 8, 1928.

The object of this invention is a heating boiler which is economical in operation and in which the coal moves by gravity from a feed hopper-into the furnace.

Boilers of this type often have the disadvantage that a considerable amount of carbon monoxide escapes thru the stack and that explosions are likely to occur in the feed hopper. 7 Moreover, it takes a considerable time before the fire can be animated.

In accordance with my present invention, which has for its object to avoid the aforesaid disadvantages, the boiler is provided with a furnace having the following 0l11If acteristic features. Provided on the one side (the front side) is the feed hopper and below the same, extending in a rearward direction with respect thereto, is a downwardly sloping guiding surface for'the coal, theslope of the said surface corresponding to the natural tallls of the fuel. Below said guiding surface may be provided an inlet opening for combustion air and on a still lower level is a cleaning and air inlet opening provided witha suitable door. Arranged on the other side (the rear side) of the furnace are three superposed openings, the upper one being for the inlet of air substantially on a level with the lower end of the slope of the incandescent coal, the central one for the inlet of air into the central part of the fire zone, whereas the lower 0 ening is for the removal of ashes and cli er and also for, the inlet-of air required for the formation of carbon monoxide. Preferably the upper air inlet opening on the rear side opens below a baflle, so that the air fed thru said openin heated, the preheating fieing favorably af-' fected by the air admitted thru the central openin heatin the coal in-the central part fire to a igh temperature. Preferably, the feed hopper. has a discharge opening in the form of a slot, the height of which does not exceed 10 em. but wh ch in practice should by preference not be higher than say 6-7 cm. Anyone skilled in the art willrecognize that this height is considerably smaller than that in known furnaces. provided with a feed hopper. r I The above arrangement of the air inlet is thoroughly preopenings relative to one another enables the perfect shown in vertical sectional elevation on the annexed drawing.

The boiler preferably is composed of a plurality of sections partly filled with water and suitably spaced so that the hot combustion gases can freely pass between them and whereupon collect in a ansverse flue leading to the chimney.

The feed hoppen 1 on the front side of the boiler has a slot shaped discharge opening 2 below which the downwardly sloping supporting and guidingsurface 3 for the coal extends thru a suitable distance. Just below the lower end of said guiding surface is an air inlet passage 4 provided with a door or a slide valve which is only opened when it is desired for the fire to be quickly anignated. On a still lower level is a wide duct 5 provided with acleaning door, said door having means for admitting an adjustable amountof combustion air into the combustion space.

On the rear side of the boiler is the flue 6 leading to the stack. The slope or talus 7 of the fuel extends from the discharge slot 2 downward to the bottom edge of an air inlet passage 8 adapted to introduce air for the combustion of any carbon monoxide that may reach the upper zone of the fire. sage 8 is the equivalent of known inlets for secondary combustion air into furnaces.

A relatively wide duct 10 near the bottom serves for the inlet of a controlled amount of air and also for the removal of clinker and ashes from the non-apertured fire plate 14 which supports the forming carbon monoxide.

Intermediate between thepassages 8 and 10 is athird inlet 9 opening into the central portion of the fire zone. Air entering thru said passage causes a high temperature of the coal in sai zone, so that the air entering thru pas sage 8 is preheated and thereby specially adapted to combine with and completely burn Said pasfire clinkers and ashes. Said amount of air principally serves for by the high temperature of the central zone due to the admission of air thru the passage 9.

As the coal sliding downward over the sloping guiding surface 3 begins to glow immediately beyond the lower end of said surface and thereby to develop a large amount of combustible gases, the passage 4 1s exceptionally adapted for the inlet of air when it is desired for the fire to be animated.

air entering thru 7 gravity moves from the hopper into the furnace, a cleaning and air inlet opening provided on the front side, a combustion air mlet provided on the rear side on a level below the discharge opening of the feed hopper but above the rear end of the talus of the fuel in the furnace, an air inlet and cleanin opening provided on the rear sidea suita le distance below the said combustion air inlet opening, an additional air inlet upon the rear 'slde adapted to introduce air to the central portion of the fire zone, and a second combustion air inlet opening'on the front side intermediate between the said downwardly sloping guiding surface and the said cleaning and air inlet opening.

In testimony whereof I aflix my signature. LEON RAINCHON.

It will be noted that the passage 4-. opens into a zone where the coal is in incandescent state. As the layer of coal here is relatively.

- thin, especially when the feed hopper has a narrow discharge slot, the fire is prevented from spreading into the feed hopper.

'WhatIclaim is 7 1. In combination with a. heating boiler, a non-apertured fire plate, a feed hopper pro-, vided on the'front side and having a discharge opening and also having a down v wardly sloping guiding surface for the coal which by gravity moves from the hopper into the furnace, a cleaning and air inlet opening provided on the front side, a combustion air. inlet provided on the rear side on a level below the discharge opening of the feed hopper but above the rear end of the talus of the fuel in the furnace, and anair inlet and cleaning opening rovided on the rear side a suitable distance elow the said combustion air inlet opening. v

2. In combination with a heating boiler, av

v non-apertured fire plate, a feed hopper provided on the front side and having a discharge opening and also a downwardly sloping guiding surface for the coal-which by gravlty moves from the hopper into the furnace, a cleaning and air inlet opening provided on the front side, a combustion air inlet provided on the rear side on a level below the discharge opening of the feed hopper but above the rear end of the talus of the fuel in the furnace, an air inlet and cleaning opening provided on the rear side a suitable disopening,

' tween the said downwardly sloping tance below the said combustion, air inlet and a second combustion air inlet opening on guiding surface and the said cleaning and air inlet opening.-

' 3. In combination with a heating boiler, a

-non-apertured fire plate, afeed hopper provided on the front side and havimgl asldischarge opening and also a downwar ing guiding 7 surface for coal which by the-front side intermediate be- 

